Remediating Boron from Synthetic Wastewater by Chemical Oxo-Precipitation Process Effect of Reaction pH, Dosages of Hydrogen Peroxide and Barium

DOI: 10.5176/2251-189X_SEES16.39

Authors: Jui-Yen Lin and Yao-Hui Huang

Abstract: With the increasing need of remediation of concentrated boron wastewater, the chemical oxoprecipitation (COP), which is capable of removing boron by precipitation at room temperature with the aid of hydrogen peroxide (H2O2), has been developed. This work aims to investigate the reaction conditions of barium-based COP, whose boron removal enhanced with time due to the phase transformation of precipitates. A wide range of reaction pHr, dosages of H2O2 and barium was tested to evaluate the optimal operating condition. The suitable pHr lied in the range 8.5 – 10.5 due to the phase transformation and the solubility of barium perborates. The dosage of H2O2 affected speciation of the perborates in both pretreatment and precipitation stage. The dosage of barium influenced the boron level based on solubility equilibrium. Hence, the suitable mole ratios of [H2O2]/[B] and [Ba]/[Ba] are 1.25 – 2.5 and 0.6 – 0.8, respectively. Under the optimal condition, the boron level could be reduced from 1000 ppm to less than 5 ppm.

Keywords: Chemical oxo-precipitation; boron removal; perborate; hydrogen peroxide;barium